The Naked Scientists

The Naked Scientists Forum

Author Topic: What's up with Heisenberg's Uncertainty Principle?  (Read 16663 times)

Offline Soul Surfer

  • Neilep Level Member
  • ******
  • Posts: 3345
  • keep banging the rocks together
    • View Profile
    • ian kimber's web workspace
What's up with Heisenberg's Uncertainty Principle?
« Reply #25 on: 12/12/2011 23:10:03 »
Geezer you are describing what became the field emission microscope something like 30 or 40 years ago it was the first to show "images" of individual atoms.
 

Offline CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6321
  • Thanked: 3 times
  • Site Moderator
    • View Profile
What's up with Heisenberg's Uncertainty Principle?
« Reply #26 on: 13/12/2011 00:39:04 »
I'm not sure about modern electron microscopy, but in the past, I thought it always required some kind of a contrast medium to be added, or having the object actually plated with some kind of a metal.

Anyway, if one can say describe the position of 1 million particles, and describe the momentum of 1 million particles...  eventually one could use a probability function to combine the position and the momentum functions.

But, in the future...  perhaps that won't be necessary.

Consider billiard balls.

If you roll a billiard ball on a table.
And, one shoots a pingpong ball to hit it. 
Based on the resulting vector of the pingpong ball, one should be able to gather a lot of information about the original billiard ball.  Certainly the point on the billiard ball that the pingpong ball hits is also important, but at least with a number of similar impacts, one would get a good description of what the billiard ball was doing.

The problem is finding the right pingpong balls!!!
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
What's up with Heisenberg's Uncertainty Principle?
« Reply #27 on: 13/12/2011 03:19:19 »
Geezer you are describing what became the field emission microscope something like 30 or 40 years ago it was the first to show "images" of individual atoms.

Rats! And I was just about to file the patent ;D
 

Offline imatfaal

  • Neilep Level Member
  • ******
  • Posts: 2787
  • rouge moderator
    • View Profile
What's up with Heisenberg's Uncertainty Principle?
« Reply #28 on: 13/12/2011 10:49:05 »
....
The problem is finding the right pingpong balls!!!

Not really no.  HUP is not about measuring accuracy - within the realm of qm it is not possible to know both the position and momentum of a particle to arbitrarily small levels of accuracy.  if a theory predicts that a particle must have an exact momentum and an exact position then the theory is wrong.  it is possible we will find in the future a deeper understanding and get around this - but that is when qm starts being replaced.  at the moment qm is one of the best tested and most accurate models ever devised - and part of the maths of that model is the non-commutative nature of certain physical variables, the practical upshot of this is that there must be an uncertainty.   heisenburgs microscope is a great heuristic but it is not the reason for this effect, it is merely a useful explanation - it isn't that we cannot be precise enough in, even theoretical, measurement; it is an underlying part of the theory.

Quote
Anyway, if one can say describe the position of 1 million particles, and describe the momentum of 1 million particles...  eventually one could use a probability function to combine the position and the momentum functions.
  There is weak measurement, averaging, constrained variables etc. but nothing gets around the HUP to any extent
 

The Naked Scientists Forum

What's up with Heisenberg's Uncertainty Principle?
« Reply #28 on: 13/12/2011 10:49:05 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length